Milledge was told to ice the injury and take several days off.
He suffered a broken hand when hit in a similar spot in Spring Training in 2004.
"They're still looking at it, but it hurts a little bit," Milledge said before knowing the outcome. "It felt like the last time when it got broken. Things happen. It's kind of disappointing to me. We'll see."
The outfielder should be OK to play again by the weekend.
The 21-year-old is having a dramatically better spring than Shawn Green, but Milledge is low-keying his hopes of securing the right-field job over Green.
"The only thing that matters is that I've got a jersey on my back," said Milledge, now hitting .352 after going 0-for-3 in the Mets' 11-3 loss to Houston at Tradition Field. "In six days, if I'm wearing a blue jersey, it means I'm in New York."
Milledge also has a home run and five RBIs. Meanwhile Green, who at 34 is 12 1/2 years older, is hitting .136 in 59 at-bats, though he has two home runs and five RBIs.
Milledge attributed his fine spring to "seeing the ball good, that's all." But he does feel last year's exposure in the big leagues is serving him well now.
"It's a year later, and I have a little experience now," he said. "I know what to expect. I'm ready."
Park adjusts: A day after Park received one of the biggest jolts of his career -- that the Mets want to use him as a reliever, not a starter -- and had a closed-door meeting with management late Saturday afternoon, he showed up at his locker as if surprised at all the media attention.
"There's nothing left to say but 'Good morning,' right?" he said.
What are his thoughts? Is he now resigned to being a reliever after 13 seasons of mostly starting?
"This is all about the team," Park said. "This isn't about myself. Yes, I have thoughts myself. I'm happiest in the rotation. But I have to do what I can do. Now my mission is being a reliever."
Park emphasized Saturday that if he thought he would never get a chance to start with the Mets, it would influence any decision he might make. But he gained some hope in the closed-door meeting when general manager Omar Minaya offered the possibility of him being used at some point to start.
Minaya said he likes Park's versatility as a guy capable of relieving and starting.
"Maybe someday the team needs a backup starter, so I have to prepare all the time," Park said.
He was asked Sunday if the Mets told him in the meeting that he has made the team. That made him blanch a little, because of its potentially negative implication if no such assurance was given.
"I guess," he finally said. "I got a guaranteed contract." Then he added, "I don't know."
There remains a possibility that Park could be traded. He has a disappointing 6.57 ERA this spring, but is coming off a sterling performance against Baltimore on Saturday, when he required just 27 pitches to throw three perfect innings.
"I always thought the spring was a time to get ready for the season," Park had said on Saturday, somewhat baffled that his performances as a veteran were apparently being judged so harshly. "I am getting ready for the season. I feel I am going to have a very good season."
Park joined the Mets as a free agent in the offseason in part because he wanted to play on a winner and in part because of New York's huge Korean population. He also was ebullient about returning to the National League, where he had his greatest career success with the Dodgers. In 2000, in fact, he was 18-10 with a 3.27 ERA.
Now Park's career path has been radically altered, at least temporarily.
"I'm going to take their advice, do it their way maybe to start the season," he said. "I understand the situation."
Sanchez situation still unclear: The Mets said on Sunday that they still have no definitive word on the condition of reliever Duaner Sanchez, who was flown to New York on Friday to have an MRI done on his sore right shoulder.
Minaya said he is hopeful of hearing something on Monday. The GM said the fact that Sanchez went to New York over the weekend made it more difficult to get a quick result.
Sanchez, who had shoulder surgery on Aug. 1, threw his first pitches of the spring on Thursday. But he was shut down after 11 pitches when he heard something pop in the shoulder. Doctors have told him it was likely scar tissue from the surgery breaking up.
Up next: Tom Glavine, with a 1.29 ERA this spring in four starts, will get his final tuneup before the regular season when the Mets play the Dodgers on Monday at 7:10 p.m. ET at Tradition Field. The Dodgers will go with Brad Penny, a familiar sight to the Mets when he played for the Marlins.
Charlie Nobles is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.